Apparatus for producing and emplacing cementitious substances



1941- w. E. ANDERSON ETAL 2,231,489

APPARATUS FOR PRODUCING AND EMPLACING CEMENTITIOUS SUBSTANCES Filed July 24, 1959 ATTORNEYS Patented Feb. 11, 1941 UNITED STATES PATENT OFFICE APPARATUS FOR PRODUCING AND EMILAC- ING CEMENTITIOUS SUBSTANCES Application July 24, 1939, Serial No. 286,240

8 Claims.

This invention relates to the art of coating surfaces with cementitious substances and the primary object is to provide a specially formed nozzle constituting a part of the apparatus by means of which a satisfactory layer of material may be emplaced.

Another important aim of this invention is the provision of the method of forming a cementitious substance immediately prior to emplacement, which method includes the novel steps of handling the materials and mixing the same so that an even flow of a plastic coating substance is obtained.

A further object of this invention is to provide a nozzle for apparatus for producing and emplacing cementitious substance, which nozzle is constructed to present a pair of intake ports that are formed and disposed to handle a supply of air and water, so that the former atomizes the latter, and so that the air will function as means for drawing sand and cement into the nozzle where such materials are rendered plastic and of proper consistency by the inclusion of water, which is inti mately injected through the unique action of compressed air which enters the nozzle through the specially formed port.

Heretofore apparatus for applying cement coating to surfaces, has usually included means for driving the sand and cement toward an applying nozzle where the desired amount of liquid or water is injected so that a cementitious material is created. The sand and cement has also been fed into the material supply hose in ways which establish a pulsating action at the outlet end of the nozzle to the end that an uneven coating is presented, which must be smoothed, if the final covering is to be uniform in thickness. It is, therefore, one of the objects of this invention to provide a method and apparatus for producing and emplacing cementitious substances that will overcome the deficiencies found in machines now in commercial use, and likewise to present apparatus which will mix sand and cement without employing as much water as heretofore has been used so that the surface being coated is rendered waterproof through the medium of a covering which is of higher density immediately adjacent to the surface being treated, and which is of progressively lower density as the outer face of the coating is approached.

This invention has for a further aim, the provision of a method of producing cementitious substances which includes the step of applying a primary coating of cement over the grains ofsand by virtue of moisture thereon, and next by finally hydrating the mass of material to render plastic the cement which has not been acted upon by the moisture on the sand at the time of the original ixin A large number of minor objects and advantages of the method and apparatus made in accordance with the present invention will become apparent to those skilled in the art as the details thereof are disclosed in the following specification, which refers to the accompanying drawing wherein:

Figure 1 is a schematic view of apparatus for emplacing cementitious substances having a nozzle therein that is made in accordance with the present invention.

Fig. 2 is an enlarged fragmentary longitudinal central sectional view through the nozzle.

Fig. 3 is a vertical cross section through the nozzle, taken on line III-III of Fig. 2; and,

Fig. 4 is a similar view taken on line IV--IV of Fig. 2.

The nozzle illustrated in the drawing has been found most satisfactory for applying a' coating of plastic material in a manner that will be more fully hereinafter set down.

The nozzle per se comprises sections 6 and 8, the ends of which are in opposed, spaced apart relation and held in such position by coupling I0 which bridges the space between sections 6 and 8, and that is secured thereto through the medium of resilient gaskets l2, one of which circumscribes sections 6 and 8 respectively.

Rings l4 circumscribe sections 6 and 8 and have machine bolts 1 6 extending therethrough into the ends of coupling l0 so that as said machine bolts are tightened, the inner annular surfaces of gaskets l2 will be drawn into gripping engagement with the respective sections. Thus, the nozzle is assembled and adjustment of the parts thereof made easy.

Sections 6 and 8 and coupling Ill are cylindrical, and the bore I8 through the body of the nozzle, consists of the passages through sections 6 and 8. This bore I8 is substantially uniform in cross section and the inner surface thereof is smooth throughout its length.

Section 8 is relatively short and the free end thereof establishes the end of the nozzle, which latter is usually maintained about 9 inches from the surface 20 being coated, as shown in Fig. 1. One end of section 6 may be, but is not necessarily in screw-threaded engagement with tubular joint 22, which in turn is attached to flexible hose 24 leading to hopper 26. The end of section 6 adjacent to the inner end of section 8 is reduced to substantially a feather-edge by tapering a portion of the length of said section to produce a frustroconical part. the outer surface 28 of which cooperates with the inner surface of coupling in in directing compressed air into bore 98.

Coupling III has an annular cavity it formed in the inner face thereof, which circumscribes the inclined face 2'8 of section 8. A similarly inclined annular surface 32 is formed on coupling to so as to present a continuous annular inclined ge 34, which when extended. will resolve into a point on the longitudinal axis of bore l8. Another annular cavity 36 created in coupling l0, circumscribes the inner end of section a and annular shoulder 38 is perpendicular to the aids of section and coupling 8 and I respectively. The end of section 8 is *disposed close to shoulder 38 so that an intake port for liquid, such as water, is established in close proximity to the intake port for air, which is created by cavity 30 and passage 38.

A tube 40 places annular cavity at in communication with a source of compressed air, such as tank 62, and a valve 3 is provided to control the passage of air to the nozzle.

A tube 66 joins cavity 36 with a tank 5% which contains the water to be used in the nozzle, and a conventional valve 58 permits the operator to determine the amount of water which is introduced into the nozzle.

An intake port for air is therefore created from the tapered end of section 6, cavity 3% and passage 3 An intake port for water is created by the inner end of section 8, cavity 36 and shoulder 38. These intake ports are continuous and circumscrlbe the bore iii in a fashion so as to cause the air to intersect the path of travel of the water after the air and water are introduced into the nozzle through the intake ports Just defined.

It is important that the air enter bore it close to the point of entrance of the water, for the water is thereby atomized and mixed with incoming sand and cement immediately prior to its escape from the nozzle. The force of compressed air must be sufficient to draw the material, such as sand and cement, from hopper 26 and also to atomize the water entering the intake port through cavity 35. I

Air at 60 pounds pressure has been found preferable and when section 8 is approximately 6 inches long, the material passing therethrough will assume a spiral path of travel through 2 turns before reaching the free end of the section.

The inner face of section 8 near its outer end may be flared at a desired angle to decrease the velocity of the material and to cause the latter to move radially from the axis of the nozzle at a greater angle as the surface being treated is approached.

An even flow of air through tube 40 insures an associated even flow of material through the nozzle and the surface 20 is therefore evenly coated when the operator manipulates the nozzle through reciprocating paths of travel. It is ordi- ,narily unnecessary to trowel or otherwise smooth the material after it has been applied to the surface being coated. The layer of cementitious substance will adhere to surface 20 and be characterized by a denser lamination directly upon the surface. This character of coating is due to the rebounding of the sand grains from surface 20 when the cementitious substance first reaches the surface being covered. The grains of sand strike surface 20 to produce a sand blasting effect and to leave directly thereon only the hydrated cement which was originally the coating over the individual grains of sand and which was a part of the mass passing through the nozzle. After the primary layer of relatively dense, substantially pure cement has adhered to \surface 20, the sand will discontinue its separating action and the coating will become less dense by virtue of the grains of sand becoming progressively greater as the distance from the surface being treated is increased.

Systems now in use commonly employ from four to ten gallons of water to every ninety-four pounds of cement. Through the application of water by the nozzle above described, two to two and one-half gallons of water per ninety-four pounds of cement is adequate. When the sand and cement is first mixed, every grain of sand is coated with a. certain amount of moisture and a fine coating of cement is collected thereon and carried to the nozzle and to the surface being treated without being dislodged. This primary coating of cement, which is on the grains of sand, has collected a certain amount of moisture that was present on the sand and the amount of water introduced at the nozzle is only that required to sumciently hydrate the mass so that the dry cement forming a part thereof is rendered plastic to the desired degree.

The success of the present invention is due not only to the manner of mixing and conveying the material, but in the nozzle as illustrated and described, and since the concepts of the invention permit embodying the same in structures having physical characteristics other than shown, it is desired to be limited only by the scope of the appended claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In apparatus for producing and emplacing cementitious substances, a tubular nozzle provided with a longitudinal bore for the passage of material, an air intake port, and a liquid intake port, said air intake port being disposed to direct air across the path of travel of the liquid entering the nozzle through the said liquid intake port, said ports both being continuous and circumscribing the bore of the nozzle.

2. In apparatus for producing and emplacing cementitious substances, a tubular nozzle provided with a longitudinal bore for the passage of material, an air intake port, and a liquid intake port, said air intake port being disposed to direct air across the path of travel of the liquid entering the nozzle through the said liquid intake port, said ports both being continuous and circumscrlbing the bore of the nozzle, said air intake being in close proximity to the liquid intake port whereby the liquid is atomized immediately prior to its combination with the material passing through the bore.

3. In apparatus for producing and emplacing cementitious substances, a tubular nozzle provided with a longitudinal bore for the passage of material, an air intake port, and a liquid intake port, said air intake port being disposed to direct air across the path of travel of the liquid entering the nozzle through the said liquid intake port, said ports both being continuous and circumscribing the bore of the nozzle, said air intake port being formed to direct a current of air toward a point on the longitudinal axis of the bore and disposed in close proximity to the liquid intake port whereby the liquid is atomized immediately prior to its combination with the material passing through the bore.

4. In apparatus for producing and emplacing cementitious substances, a tubular nozzle provided with a longitudinal bore for the passage of low water content cementitious material, a port for admitting compressed air into the bore, and a port for admitting water into the bore, said ports having their discharge openings in the side of the bore and disposed in juxtaposition with the paths of travel of their discharge intersecting to cause the air to atomize the water as it enters the bore and prior to combination with the cementitious material passing therethrough; and means for controlling the supply of air and water respectively. v

5. In apparatus for producing and emplacing cementitious substances, a nozzle having a cylindrical, smooth bore of substantially uniform cross section adapted to be connected with a source of supply of sand and cement, said'nozzle being provided with an air intake port and a water intake port, said ports having their discharge openings in the side of the bore and disposed in juxtaposition with the paths of travel of their'discharge intersecting whereby the water intersects the path of travel of the air at the side,

of the bore to atomizejthe former priorto its combination with the sand and cement passing through the bore, said nozzle constituting a sectional body; and a. coupling having an inner surface formed to cooperate with the ends of the sections of said body to produce the aforesaid ports.

6. In apparatus for producing and emplacing cementitious substances, a nozzle having a cylindrical, smooth bore of substantially uniform cross section adapted to be connected with a source of supply of sand and cement, said nozzle being provided with an air intake port and a water intake port, said ports having their discharge openings in the side of the bore and disposed in juxtaposition with the paths of'travel of their discharge intersecting whereby the water intersects the path of travel of the air at the side of the bare to atomize the former prior to its combination with the sand and cement passing through the bore, said nozzle constituting a pair of sections having ends in opposed spaced relation; and a coupling to clamp said sections in place, said coupling being provided with cavities in the. inner surface thereof to cooperate with the ends of said sections to produce continuous annular intake ports for the air and water respectively.

7. In apparatus for producing and emplacing cementitious substances, a nozzle having a cylindrical, smooth bore of substantially uniform cross section adapted to be connected with a source of supply of sand and cement, said nozzle being provided with an air intake port and a water intake port, said ports having their discharge openings in the side of the bore and disposed in juxtaposition with the paths of travel of their discharge intersecting whereby the water intersects the path of travel of the air at the side of the bore to atomize the former prior to its combination with the sand and cement passing through the bore, said nozzle constituting a pair of cylindrical sections having ends in opposed spaced apart relation; and a cylindrical coupling in telescoped relation with the sections, said coupling being provided with a pair of annular cavities in the inner face thereof, one of said cavities circumscribing the end of one section, the other cavity circumscribing the end of the other section.

8. In apparatus for producing and emplacing cementitious substances, a nozzle having a cylindrical, smooth bore of substantially uniform cross section adaptedto be connected with a source of supply of sand and cement, said nozzle being provided with an air intake port and a water intake port disposed in close proximity whereby the water intersects the path of travel of the air to atomize the former, said nozzle constituting a pair of cylindrical sections having ends in opposed spaced apart relation; and a cylindrical coupling in telescoped relation with the sections, said coupling being provided with a pair of annular cavities in the inner face thereof, one of said cavities circuinscribing the end of ,one section, theother cavity circumscribing the end of the other section, the outer surface of one section near the end thereof being tapered to direct air entering the cavity circumscribing the said end toward a point on the longitudinal axis of the bore of the nozzle.

WILLIAM E. ANDERSON. FRANCIS C. DOWNEY. 

